Disazo coloring-matter.



5 .Dyes wool from the N1TED STATES Patented October 20, 19053;.

PATENT FFICE.

ERHART SOHLEICHER AND AUGUST DORRER, OF LUDWIGSHAFEN-ON-THE- RHINE,GERMANY, ASSIGNORS TO THE BADISOI-IE ANILIN UND SODA FABRIK, OFLUDWIGSHAFEN-ON-THE-RHINE, GERMANY, A CORPORA- TION OF BADEN.

DISAZO COLORING-MATTER.

SPECIFICATION forming part of Letters Patent No. 741,936, dated October20, 1903.

Application filed July 17, 1903- Serial No. 166,011. (No specimens.)

T0 all whom it nuty concern:

Be it known that we, ERHART SCHLEIGHER, doctor of philosophy, a subjectof the Duke of Saxe-Meinin gen, and AUGUST D ORRER, doctor ofphilosophy, a subject of the King of Wiirtemberg, both residing atLudwigshafen-onthe-Rhine, in the Kingdom of Bavaria, Empire of Germany,have invented new and useful Improvements in Disazo Coloring-Matter, ofwhich the following is a specification.

We have discovered that 1.5 dihydroxynaphthalene will unite with twomolecular proportions of a diazotized amido-alphyl-sulfo-acid to formvaluable disazo coloring-matters. The amido-alphyl-sulfo-acids which areparticularly suited for the purposes-of our invention are sulfanilicacid, naphthionic acid, and 2.8 naphthylamin sulfo-acid.

The coloring-matters obtained according to our invention yield, onreduction with stannous chlorid and hydrochloric acid, a brown tobrown-yellow body, which is the hydrochlorid of diamidodihydroxynaphthalene. It is soluble in water when shaken with air,yielding a blue solution. It dissolves in sodium-acetate orsodium-carbonate solution, yielding a blue to blue-violet solution. Ontriturating it with water containing a little hydrochloric acid andadding a few drops of ferric-chlorid solution to the paste a strong bluecoloration is at once formed. The addition of sodium nitrit to the pasteproduces a yellow-red coloration.

The following table gives some of the properties of the disazocoloring-matters obtained according to our invention:

2.8 naphthylaminsulfo-acid.

N aphthionic Sultanilic acid. Held Cololr of the aqueous Red VioletBlue-red.

ution.

Brownish but Violet Red-violet.

acid-bath. deaux.

Brownish bor- Red-violet.

. deaux.

Shades been me on treatment with potassium bi ch r omate and aceticacid.

Violet-black illustrate the nature of our invention, which, however, isnot confined to these examples. The parts are by weight.

Example 1: Diazotize one hundred and ninety-five (195) partsofanhydroussulfanilicacid sodium salt and remove the free mineral acidfrom the diazo solution or suspension by means of an excess of sodiumacetate. Cool the solution with ice and add thereto one hundred andsixty (160) parts of 1.5 dihydroxynaphthalene in the form of a three (3)per cent. paste. noazo coloring-matter results. To this solution addcaustic-soda lye in large excess, and then while cooling well with iceaddthe diazo solution or suspension obtained from a further one hundredand ninety-five (195) parts of anhydrous sulfanilic acid sodium salt.The solution, which is at first red-violet, becomes blue-violet. Whencombination is ended, acidify the whole with hydrochloric acid andprecipitate the coloring-matter by means of common salt. It dies woolfrom the acid-bath brownish bordeaux. The monoazo coloring-matter canalso be obtained from a solution made alkaline by means of carbonate ofsoda or caustic soda.

Instead of producing the above coloringmatter in two phases it can beproduced in one operation, as explained in the following Example 2.

Example 2: Diazotize one hundred and ninety-five (195) parts ofanhydroussulfanilicacid sodium salt and add the diazo solution orsuspension 10 an ice-cold solution of eighty (80) parts of 1.5dihydroxynaphthalene in one thousand (1,000) parts of ca ustic-soda lyecontaining thirty-five (35) percent. of NaOH and ten thonsand(l0,000)parts of water. The formation of the coloring-matter begins at once andis soon completed. Isolate the coloring-matter as in Example 1.

Example 3: Diazotize two hundred and forty'five (245) parts of anhydroussodium naphthionate and remove the free mineral acid from the diazosuspension by means of an excess of sodium acetate. 0001 the liquid withice and add thereto a solution of one hundred and sixty (160) parts of1.5 dihydroxynapthalene and eighty (80) parts of caustic soda in water.A paste of a monoazo coloring-matter results. To this paste add Ayellow-red solution of a mocaustic-soda lye in large excess, and thenwhile cooling well with ice add the diazo suspension obtained from afurther two hundred and forty-five (245) parts of anhydrous sodiumnaphthionate. The solution, which is at first blue-violet, becomes pureblue. When combination is ended, precipitate the coloring-matter bymeans of common salt and purify, if desired, by redissolving it andreprecipitating it. The monoazo coloring-matter can also be obtainedfrom a solution made alkaline by means of carbonate of soda or causticsoda.

Instead of producing the above coloringmatter in two phases it can beproduced in one operation, as explained in the following Example 4:.

Example 4: Diazotize two hundred and forty-five (2&5) parts of anhydroussodium naphthionate and add the diazo suspension to an ice-cold solutionof eighty (80) parts of 1.5 dihydroxynaphthalene in one thousand (1,000)parts of caustic-soda lye containing thirty-five (35) per cent. of NaOHand ten thousand (10,000) parts of water. The formation of thecoloring-matter begins at once and is soon completed. Isolate thecoloringmatter as in Example 3. In place of naphthionic acid in thisexample the equivalent quantity of 2.8 naphthylamin sulfo-acid can beemployed, yielding a coloring-matter of the aforementioned properties.

We claim 1. Coloring-matter which can be derived from 1.5dihydroxynaphthalene and two molecular proportions of ahereinbefore-mentioned diazotized amido-alphyl-sulfo-acid, whose aqueoussolution is red to violet, which dyes wool from the acid-bath brownishbordeaux to violet, which shades after treatment with potassiumbichromate and acetic acid are brownish bordeaux to violet-black; andwhich on reduction with stannous chlorid and hydrochloric acid yieldsdiamido-dihydroxynaphthalene.

2. Coloring-matter which can be derived from 1.5 dihydroxynaphthaleneand two molecular proportions of diazotized naphthionic acid, whoseaqueous solution is violet, which dyes Wool from the acid-bath violet,which shades after treatment with potassium bichromate and acetic acidare violet-black; and which on reduction with stannous chlorid andhydrochloric acid yields diamido-dihydroxynaphthalene.

In testimony whereof we have hereunto set our hands in the presence oftwo subscribing witnesses.

ERHART SOHLEIOHER. AUGUST DORRER.

